A conventional torque wrench is adjusted to set a desired torque value, and when an operating force is over a set torque value, the torque wrench makes sounds to remind a user. The conventional torque wrench contains a rotatable controlling member for driving a screw rod fixed in an extension of the torque wrench to rotate, and then a sliding block screwed with the screw rod moves to different positions so that a spring is pressed by the sliding block to adjust a torque value.
The torque value is displayed by the following types:
1. A numerical scale is marked on a handle of the torque wrench, but a size of an outer peripheral side of the handle is limited, for example, only some linear scales and larger torque values are marked on the outer peripheral side of the handle, so a precise scale cannot be marked on the handle.
2. The torque wrench is provided with a battery to display the torque value electronically, but the battery has to be replaced after a period of using time.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.